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Lili Cosic

@lilicosic.com
1.6K followers 124 following 384 posts

👩🏻‍💻 Senior Database Engineer @InfluxData working on InfluxDB v3 Enterprise. I enjoy talking about databases, observability and good food. Previously @ HashiCorp, Red Hat. Now in Berlin 🇩🇪 from 🇸🇮

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Lili Cosic @lilicosic.com · 24/09/2026
I ground the beans, refilled the water, put in a new filter into the coffee machine. I come back when it makes the beep and the water is clear… turns out ai left the beans out on the countertop. How is your day going?
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Mark Somers @marksomers.bsky.social · 06/09/2026
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Lili Cosic @lilicosic.com · 01/09/2026
I thought there was rain again outside, nope was just cargo build on my MacBook. Gets me everytime.
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Andrew Lamb @andrewlamb1111.bsky.social · 28/08/2026
DataFusion 55 Release: datafusion.apache.org/blog/output/... Possibly includes a humble brag
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Dash0 @dash0.com · 17/08/2026
Dash0 welcomes Polar Signals to the team. They built the leading continuous profiler for cloud native workloads, with GPU and CUDA support, and created Parca, the open source profiling project behind it. Profiling will live natively in Dash0, next to traces, metrics and logs. eu1.hubs.ly/H0xG-d70
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Lili Cosic @lilicosic.com · 17/08/2026
So proud of everyone at Polar Signals! 🧊 congrats to Dash0! An unstoppable observability combination!👏
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Polar Signals @polarsignals.com · 17/08/2026
🚀 Incredibly excited to share: Polar Signals is joining Dash0! 🧊 www.polarsignals.com/blog/posts/2...
polarsignals.com
Polar Signals is Joining Dash0 | Polar Signals
The next chapter for continuous profiling, our database, and the team
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Andrew Lamb @andrewlamb1111.bsky.social · 21/07/2026
Can you accelerate queries when your data is *partially* sorted (and e.g. you don't want to have to resort it). Yes. Qi Zhu and I explain how in: datafusion.apache.org/blog/2026/07...
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Andrew Lamb @andrewlamb1111.bsky.social · 13/07/2026
DataFusion is now a real thing -- en.wikipedia.org/wiki/Apache_...
en.wikipedia.org
Apache DataFusion - Wikipedia
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Andrew Lamb @andrewlamb1111.bsky.social · 06/07/2026
I recently joined Rich Bowen of the ASF to talk about Apache DataFusion's origins and increasing popularity YouTube is at youtu.be/6E5ER09F5SQ Just audio at wp.me/p8gHED-57w
youtu.be
Apache DataFusion, with PMC Chair Andrew Lamb
YouTube video by The ASF
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Alfonso Subiotto @asubiotto.com · 24/06/2026
This was a fun one! For @polarsignals.com's latest hackathon, I wrote an FSST decompression CUDA kernel and then optimized it by profiling with our new GPU PC sampling feature. www.polarsignals.com/blog/posts/2...
polarsignals.com
My Journey Optimizing a CUDA Kernel with Polar Signals | Polar Signals
A storage engineer's descent into warp stalls, memory throttles, and aligned stores
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Polar Signals @polarsignals.com · 10/06/2026
🚀 Launching today: GPU PC sampling in production. Instruction-level profiling telling you why and where warps stall. Whether it is memory latency, scoreboard waits, or barriers. 🧊 Previously NSight-only territory. Now running in prod with low overhead. www.polarsignals.com/blog/posts/2...
polarsignals.com
Open-Source Low-Overhead NVIDIA CUDA PC Sampling | Polar Signals
And how we made it happen
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Lili Cosic @lilicosic.com · 08/06/2026
Is it just me, or would the ability for author to drag and reorder files in GitHub PRs save so much time during code reviews?
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Lili Cosic @lilicosic.com · 03/06/2026
This quote by Douglas Adams is still my favourite and always so relevant: "I love deadlines. I love the whooshing noise they make as they go by."
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Cynthia Dunlop @cynthiadunlop.bsky.social · 27/05/2026
Have a cool performance optimization you want to share with a community of latency-obsessed engineers? The P99 CONF call for speakers ends this week. 👀 Details at www.p99conf.io/2026/04/01/b...
p99conf.io
Obsessed with Low Latency? Be Part of P99 CONF 2026
Obsessed with high performance and low latency engineering? Discuss your experiments, optimizations, ideas, and lessons learned with ~30K like-minded engineers… at P99 CONF 2026!
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Polar Signals @polarsignals.com · 06/05/2026
🤖Using Polar Signals Cloud and Claude Code to autonomously optimize your code every day! 📈 Also: Check out our new website! What do you think? www.polarsignals.com/blog/posts/2...
polarsignals.com
Autonomous Optimization with Claude Code | Polar Signals
Optimize your infrastructure autonomously every day with Claude Code and Polar Signals
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Johan Brandhorst-Satzkorn @jbrandhorst.com · 05/05/2026
SREs hate this one YAML annotation: oblique.security/blog/the-per...
oblique.security
The performance bug hiding in our billing settings | Oblique
How we spent two months debugging Cloud Run latency, built out our tracing along the way, and learned the fix was one line of YAML.
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Andrew Lamb @andrewlamb1111.bsky.social · 05/05/2026
Using Tokio for CPU-Bound Tasks (Works Really Well) youtu.be/FeqRdDG1Y7g (has nothing to do with AI, just scheduling and Database plans)
youtu.be
Using Tokio for CPU-Bound Tasks (Works Really Well) May 2026
YouTube video by Andrew Lamb
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Oblique @oblique.security · 30/04/2026
A coworker disappearing into a cave and coming back with 12,000 lines of code you have to review is cause for a heart attack. But, how do you handle the ever-increasing volume of code reviews? Our engineering team wrote down how we navigate code reviews at Oblique: oblique.security/blog/how-obl...
oblique.security
How Oblique handles code review etiquette | Oblique
Code reviews aren’t just about ensuring engineering quality, they’re also about building team culture. Focus on communication and understanding rather than nit-picking style quirks.
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OpenTelemetry @opentelemetry.io · 27/04/2026
OpenTelemetry ❤️ Prometheus! The #OTel and #Prometheus projects are strengthening interoperability. 🛠️ Building with both? Check out our client library comparison, plus updates on Prometheus compatibility and exporter spec stabilization. Links in 🧵! 🗳️ Running both? Take our survey! buff.ly/XhVm0Fg
docs.google.com
Survey: 🔭OpenTelemetry ↔ 🔥Prometheus Interoperability
Privacy notice: The data collected in this survey will be anonymised and publicly shared in the GitHub repositories prometheus-community/ux-research and opentelemetry/sig-end-user under the CC0 1.0…
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Marko Bevc @marko.social · 26/04/2026
"Slovenia stands alongside Ireland, Spain, the Netherlands and Iceland in refusing to take part in this year’s 70th edition of the competition due to the EBU allowing Israel to compete despite criticisms of its conduct in the war in Gaza." 👏 www.euronews.com/culture/2026...
euronews.com
Slovenia to broadcast films about Palestine instead of Eurovision
Slovenia joins Ireland and Spain in not broadcasting this year’s Eurovision Song Contest after a decision to boycott the live event over Israel’s participation.
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Alfonso Subiotto @asubiotto.com · 28/04/2026
We've been working on a major schema migration at @polarsignals.com that has unlocked some pretty wild improvements. Apart from a 50% (!!) reduction in storage size thanks to logical compression in vortex.dev, there has been a dramatic improvement in query performance.
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Jimmy Zelinskie @jimmy.zelinskie.com · 17/04/2026
who decided to call it firecracker-containerd and not crackernetes?
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Andrew Lamb @andrewlamb1111.bsky.social · 07/04/2026
DataFusion 53.0.0 is released: datafusion.apache.org/blog/output/...
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Polar Signals @polarsignals.com · 10/03/2026
🚀 Introducing the Polar Signals VS Code extension! See CPU time, memory allocations, and more as inline annotations, right next to your code. Works with Polar Signals Cloud and self-hosted Parca. www.polarsignals.com/blog/posts/2...
polarsignals.com
Do more with less. | Polar Signals
Polar Signals Cloud is an always-on, zero-instrumentation continuous profiling for CPU, GPU, and Memory that helps improve performance, understand incidents, and lower infrastructure costs.
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Andrew Lamb @andrewlamb1111.bsky.social · 27/02/2026
Here is a new blog about Parquet Variant, including use case, and shredding examples parquet.apache.org/blog/2026/02...
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Lili Cosic @lilicosic.com · 25/02/2026
After a few years focusing on cloud platforms, I’ve moved back to core database engineering in January! I wanted to move to our InfluxDB 3 team because I missed working on DBs. It’s been an intense start to 2026, but the team gave me a warm welcome and I was able to start contributing quickly. 🦀
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Lili Cosic @lilicosic.com · 11/02/2026
TIL: notary in Germany reads out the entire contract before you sign it. It sounds like my personal hell: sitting still for 2 hours while someone reads out loud a contract in German, and then you pay them for the privilege. 🫠
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Soraya Nadia McDonald @soraya.press · 09/02/2026
Benito is a threat b/c he makes art so alluring and enjoyable you want to understand everything about it and then you end up learning about sugar and slavery and colonialism and the Taínos and Hawaii and then you probably have some thoughts of your own, and that's why art is powerful and dangerous
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Polar Signals @polarsignals.com · 01/02/2026
Polar Signals at #FOSDEM 2026 day 2! Both talks in the Rust room. Profiling Rust applications with Parca Brennan at 12:30 @ UB2.252A (Rust) fosdem.org/2026/schedul... Frederic at 16:00 @ UB2.252A (Rust) Random seeds and state machines: An approach to DST in Rust fosdem.org/2026/schedul...
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Polar Signals @polarsignals.com · 31/01/2026
Polar Signals at #FOSDEM 2026 day 1! Tommy at 12:30 @ H.1308 (eBPF) OOMProf: Profiling Go heap memory at OOM time fosdem.org/2026/schedul... Thor at 17:25 @ UB2.252A (Databases) From Disks to Distributed: Our Journey of Database Evolution in the Cloud fosdem.org/2026/schedul...
fosdem.org
FOSDEM 2026 - OOMProf: profiling Go heap memory at OOM time
OOMProf is a Go library that installs a eBPF programs that listen to Linux kernel tracepoints involved in OOM killing and records a memory profile before your Go program is dead and gone. The memory…
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Frederic Branczyk @brancz.com · 27/01/2026
Very excited for this year's #FOSDEM! Lots of talks by Polar Signals folks:
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InfoQ @infoq.com · 23/01/2026
1/5 ➡️ Why Rust Will Help You Deliver Better Low-latency Systems and Happier Developers with Andrew Lamb bit.ly/47kgmwU @andrewlamb1111.bsky.social #RustLang #LowLatency
bit.ly
Why Rust Will Help You Deliver Better Low-latency Systems and Happier Developers
Andrew Lamb, a veteran of database engine development, shares his thoughts on why Rust is the right tool for developing low-latency systems, not only from the perspective of the code’s performance, bu...
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Bryan Boreham @bboreham.bsky.social · 19/01/2026
The hard things in computing: * cache eviction * naming things * figuring out which of your paying customers is DOSing your service
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Lili Cosic @lilicosic.com · 17/01/2026
Super exciting to see two speakers from InfluxData here! 🎉
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Lili Cosic @lilicosic.com · 16/01/2026
The irony of shortening my Balkan name to "Lili" for the convenience of others, only to have people spell it "Lilli." 🫠
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Chris Short @chrisshort.net · 12/01/2026
I was laid off last week. I'm excited to start a new chapter where I can put my knowledge and dedication to work. I believe every chapter closes to make room for something more rewarding. I'm keen to discover the next opportunity. Learn more: www.linkedin.com/pos... #OpenToWork
linkedin.com
Chris Short Résumé | Chris Short
I'm looking for a new role! With 30 years in the industry, I'm excited to start a new chapter. I believe every ending creates space for something more rewarding. I love taking intricate technical concepts and making them click for people. Whether through content, community work, or strategic enablement, my best days are when I help practitioners understand powerful tools and drive adoption. What I Bring My career bridges deep technical capability with clear communication: Content That Drives Adoption: I've created 700+ hours of video content and maintain newsletters reaching 6,300+ subscribers (DevOps'ish, EKS.news). I've given countless talks that translate complexity into clarity, driving revenue and reducing support load. Community Impact: As a former CNCF Ambassador and current Kubernetes Contributor Comms co-lead, I led communications for the K8s registry migration, achieving zero downtime globally. I've onboarded dozens of contributors and helped shape how we discuss cloud native tech. Shipping Big Things: I led the AWS re:Invent 2023 Kubernetes track with 50+ speakers and 30+ sessions, improving CSAT scores. I drove Valkey's developer engagement strategy—it's now the de facto Redis fork worldwide. I organized and hosted GitOpsCon EU 2021 with 300+ attendees, making it a top 2 KubeCon Day 0 event. Earlier in my career, I led a $1M AWS cloud migration with measurable savings. Technical Depth: I bring 30 years across IT ops, DevOps, the Kubernetes/CNCF ecosystem, open source tooling (Linux/Ansible), multi-cloud environments, and container technologies. Bonus: I'm now AI-enabled. What I'm Looking For Roles where technical experience meets storytelling. Three must-haves: customer-facing, cloud-native, and storytelling-heavy. Developer Advocate, Technical Marketing Manager, and Product Marketing Manager roles fit perfectly. Solutions Architect positions could work if they involve customer-facing technical communication and enablement. I'm especially interested in companies building cloud native tools or Kubernetes-based platforms—that's my playground. The Remote Piece I need remote work as a disabled veteran managing nerve/spine damage, PTSD, and anxiety. My Detroit care team keeps me going. I'm near a major Delta hub and have done same-day international trips when needed. Remote doesn't mean unavailable—I'm committed to being responsive and engaged. Let's Connect After three decades, I know my value: I make complex tech accessible, build communities around products, and drive adoption through authentic technical storytelling. I'm available now for full-time roles; contract work could also fit. If you're building something great and need someone who translates technical depth into business impact, let's talk. Contact: https://lnkd.in/g-CbGNdT Resume: https://lnkd.in/gzdjdQxB Here's to embracing new chapters and exciting challenges ahead.
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Andy Pavlo @andypavlo.bsky.social · 05/01/2026
I've posted my latest recap of the world of databases: www.cs.cmu.edu/~pavlo/blog/... All the hot topics from the last year: • More Postgres action! • MCP for everyone! • MongoDB gets litigious with FerretDB! • File formats! • Market movements! • The richest person in the history of the world!
cs.cmu.edu
Databases in 2025: A Year in Review
The world tried to kill Andy off but he had to stay alive to to talk about what happened with databases in 2025.
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Lili Cosic @lilicosic.com · 05/01/2026
I make it a point to be anywhere but Berlin on December 31st (IYKYK)! This year it was Bologna, amazing food, charming streets and celebrations among Italians for new year is so unique!
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Lili Cosic @lilicosic.com · 31/12/2025
Last couple of sunsets of 2025.
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Polar Signals @polarsignals.com · 30/12/2025
We cut cross-zone traffic for SLO monitoring by 90% using Prometheus subquery optimization. The trick: pre-aggregate data locally instead of shuffling 55M raw samples to Thanos queriers. Coming soon to Pyrra! 🚀 www.polarsignals.com/blog/posts/2...
polarsignals.com
Do more with less. | Polar Signals
Polar Signals Cloud is an always-on, zero-instrumentation continuous profiling for CPU, GPU, and Memory that helps improve performance, understand incidents, and lower infrastructure costs.
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Alfonso Subiotto @asubiotto.com · 23/12/2025
A simple 50-line code change saves us 30% of CPU across our whole infrastructure. This is the magic of system-wide profiling with @polarsignals.com. Easy to spot, easy to fix.
github.com
performance[vortex-array]: don't call is_valid to count bytes in varbinview by asubiotto · Pull Request #5814 · vortex-data/vortex
I noticed that the better blocks compressor uses count_referenced_bytes which calls is_valid on each view and results in an expensive scalar_at call. This was 30% of our system-wide CPU usage over ...
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Polar Signals @polarsignals.com · 18/12/2025
🚀 We recently announced our NVIDIA CUDA always-on profiler. Check out this blog on how to try it out super quickly with your CUDA workload today!🧊 www.polarsignals.com/blog/posts/2...
polarsignals.com
Profiling NVIDIA CUDA in Kubernetes
The easiest way to get started Profiling CUDA in Kubernetes
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InfluxDB @influxdb.com · 18/12/2025
🆕 InfluxDB 3.8 is here! We’ve focused on 2 things: simplified deployments & smarter AI. What’s inside: ▪️ Linux Native ▪️ K8s Ready ▪️ Better Insights Whether you’re starting on open source Core or scaling with Enterprise, 3.8 is built to run where you do. Read the breakdown: bit.ly/4ajCxon
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Qian Li @qianli.dev · 15/12/2025
Thanks Andy! We published the recording here www.youtube.com/watch?v=RnQK... cc @alona.page @wpaven.bsky.social
youtube.com
DBOS: 2025 Year in Review with Mike Stonebraker and Andy Pavlo
YouTube video by DBOS-Inc
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Lili Cosic @lilicosic.com · 13/12/2025
Gemini is far the best for every life day tasks, assisting, planning, etc. And Claude code is far the best for coding and other tech tasks. Did I miss anything that is better or even comes close to it?
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Lili Cosic @lilicosic.com · 12/12/2025
End of an era. 😢
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Lili Cosic @lilicosic.com · 11/12/2025
Its that time of the year where I keep using "by EOY" instead of "by EOD".
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Andy Pavlo @andypavlo.bsky.social · 05/12/2025
Do you like databases? Do you want to hear two database professors rant about them? Do you need one of those professors to have a Turing Award for databases? If yes, then join Mike Stonebraker and I next Wed Dec 10 @ 1:00pm EST for database hot takes: www.dbos.dev/webcast-2025...
dbos.dev
2025 in Review with Mike Stonebraker and Andy Pavlo
Webcast Dec 10: DBMS researchers Mike Stonebraker (MIT / DBOS) and Andy Pavlo (CMU) discuss which data and CS trends are heating up or cooling down heading into 2026.
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Lili Cosic @lilicosic.com · 05/12/2025
When the cloudflare own page is down you know it is bad. 🫠 hugops to everyone oncall!
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