WHO YOU'RE HIRING
DevPeer is the independent engineering consultancy of Tomasz Posłuszny. I read messy, undocumented systems fast, make architecture calls you can defend to your board, and then build the difficult part myself — I don't hand it off. Engagements typically run two to four days a week alongside your existing team: your engineers review my pull requests, I review theirs, and the knowledge stays with you when I leave.
WHAT I BUILD
WHERE CLIENTS BRING ME IN
Production AI and Agents
Agent architectures that survive contact with real users: multi-step tool execution, provider failover, context management and safety boundaries. I have shipped a browser agent to the Chrome Web Store, not a demo video.
Backend and Data Platforms
Ingestion, streaming, analytics and cloud infrastructure for data-intensive products. Designed around the traffic you actually get and the budget you actually have, with the operational story worked out before launch.
Performance-Critical Systems
When latency or infrastructure cost is the product constraint, I profile, redesign and rebuild the hot path. On one production web-extraction platform that meant 2.5x lower rendering latency and better hardware utilisation.
Chromium Engineering
Deep browser-engine work: Chromium forks, rendering internals, and the release and update infrastructure behind shipping desktop products on Windows and macOS while staying in sync with upstream.
SELECTED WORK
BROWSER PRIVACY FEATURE
Chromium and Firefox fork modifications that override, at engine level, the JavaScript APIs used for tracking and fingerprinting.
WHERE AI PRODUCTS BREAK
Most AI products work in a demo and break in production. Tool calls fail silently and the agent treats the error as a result, then reports work it never did. A prompt that worked on one model behaves differently on the next. Latency triples halfway through a multi-step workflow, and serving cost — not model quality — starts governing your unit economics. That is the layer I work in: agent loops that recover from failure, evals that tell you whether a change actually helped, context that stays inside the window, and a cost per request you can forecast.
HAVE A PROBLEM WORTH SOLVING?
GET IN TOUCH
Tell me about the system you are building, or the one that is slowing you down. I read every message myself and reply within one business day.
By sending an inquiry, you agree to the processing of your personal data and to receiving further correspondence from me.
© 2026 DevPeer. All rights reserved.