From a4b0542bbdf8dda11ec489809c131f2603801a62 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=C5=81ukasz=20Niemier?= <~@hauleth.dev> Date: Sat, 25 Jul 2026 22:06:58 +0200 Subject: [PATCH] CV improvements --- content/cv/_index.md | 146 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 117 insertions(+), 29 deletions(-) diff --git a/content/cv/_index.md b/content/cv/_index.md index fa74f46..ee415e0 100644 --- a/content/cv/_index.md +++ b/content/cv/_index.md @@ -6,11 +6,14 @@ no_comments = true sitemap = false +++ +Principal Elixir Developer + **Email:** **Website:** **GitHub**: **Tangled**: +**LinkedIn**: {% section() %} ## Summary @@ -24,62 +27,73 @@ engineering, distributed systems, and fault-tolerant platforms. Distributed Systems · BEAM/OTP · Performance Engineering · System Architecture ˙ Technical Mentoring {% end %} +{% section() %} ## Technical Skills **Core Technologies**: Elixir, Erlang/OTP, Phoenix, Ecto, PostgreSQL **Additional Experience**: Rust, Terraform, Nomad, Consul, Docker, Nix/NixOS +{% end %} {% section() %} ## Open Source & Ecosystem Contributions +Recognized contributor to the BEAM ecosystem through open-source development, +conference speaking, and standards working groups. + - Contributor to Elixir core - Contributor to Erlang/OTP - Contributor to Ecto - Changes accepted across logging, networking, tooling, and language features - Member of Erlang Ecosystem Foundation Observability Working Group - Member of OpenTelemetry Erlang Working Group -- Speaker at CodeBEAM V America - *Who supervises supervisors?* -- Speaker at ElixirConf EU 2022 - *"`config.exs` is simple" and Other Lies* -- Guest at Thinking Elixir Episode 149 - *Elixir's Unified Logger* - *Member of the Year* on Elixir Forum in years 2019–2025 {% end %} ## Professional Experience {% section() %} -### DockYard - Consultant +### Hauleth.dev - Owner -2025 +Nov 2016 - Present -- Architectural analysis of client product codebase with preparation of system - analysis with detailed report -- Proposed several improvements in areas of security, architecture design, fault - tolerance, and scalability +- Publish technical articles on Elixir, Erlang, Rust, distributed systems, and + culture +- Develop and maintain open-source projects used by the BEAM community +- Deliver conference talks and participate in ecosystem working groups +{% end %} + +{% section() %} +### DockYard - Elixir Consultant + +Nov 2025 – Dec 2025 + +- Performed architecture and security review of a large Elixir codebase +- Delivered a detailed report with recommendations covering architecture, + scalability, fault tolerance and security {% end %} {% section() %} ### Supabase - Lead Elixir Developer -2023–2025 +Nov 2023 – Jun 2025 - Redesigned metrics gathering architecture resulting in 10× throughput improvement and lower infrastructure costs -- Updated used OTP and Elixir versions from OTP 24 to OTP 27 and Elixir from - 1.14 to 1.18 -- Reduced usage of mocking in tests to improve tests performance and volatility, - resulting in reduced CI usage and improved developer experience +- Upgraded production platform from OTP 24 to OTP 27 and Elixir 1.14 to 1.18 +- Simplified test architecture, reducing CI resource usage while improving + reliability and developer experience - Implemented e2e tests against existing 3rd-party PostgreSQL clients to improve platform reliability for external clients - Led design and implementation of multi-region deployment strategy improving platform fault tolerance and availability -- Mentored team about Erlang and Elixir profiling tooling and performance - analysis for hot code paths +- Mentored engineers in Erlang/OTP profiling and performance analysis of + production systems {% end %} {% section() %} -### Logflare - Senior Elixir Developer +### Supabase - Senior Elixir Consultant -2023 +Mar 2023 – Nov 2023 - Implemented on-the-fly decompression of incoming data that improved ingestion possibilities and reduced transfer usage by up to 50% @@ -93,14 +107,16 @@ Distributed Systems · BEAM/OTP · Performance Engineering · - Replaced dynamic generation of connection modules for PostgreSQL storage system with Ecto's dynamic repositories to prevent DoS attack via atom exhaustion +- Maintained Rust NIF bindings to `pg_query` SQL parser library {% end %} {% section() %} ### Eiger - Consultant -2022–2023 +Aug 2022 – Feb 2023 - Implemented Interledger protocol for cross-chain financial transactions +- Implemented Elixir FFI bindings to Rust library Zcash - Led implementation of GraphQL APIs for blockchain data platforms - Led small engineering team and delivered developer tooling for smart contract ecosystems @@ -109,32 +125,42 @@ Distributed Systems · BEAM/OTP · Performance Engineering · {% section() %} ### Erlang Solutions/Kloeckner GmbH - Consultant -2021 +Apr 2021 – Dec 2021 - Optimised database query performance by 15% via PostgreSQL structure analysis - and improved indices usage. + and improved indices usage - Prepared company-wide learning materials for PostgreSQL utilisation and configuration. Mentored team about their SQL queries -writing skills. + writing skills {% end %} {% section() %} -### Kobil GmbH - Erlang/Elixir Consultant +### Remote.com - Elixir Developer -2019–2020 +Oct 2020 – Apr 2021 + +- Refactored and fixed multi-currency handling logic within the payment + processing subsystem, improving correctness and maintainability of currency + conversion code paths +{% end %} + +{% section() %} +### Kobil GmbH - Erlang/Elixir Developer + +Mar 2019 – Sep 2020 -- Maintenance of open-source MongoDB driver -- Implemented support for transactions in MongoDB driver for Elixir -- Migrated build system from Rebar3 to Mix to improve integration with Elixir - dependencies - Created Hex-compatible package registry for serving internal packages together with HexDocs-compatible documentation viewer +- Migrated build system from Rebar3 to Mix to improve integration with Elixir + dependencies +- Implemented support for transactions in MongoDB driver for Elixir +- Maintenance of open-source MongoDB driver {% end %} {% section() %} ### AppUnite - Full-stack Developer/DevOps -2016–2019 +Nov 2016 – Mar 2019 - 2× performance improvement by optimising PostgreSQL usage by reducing geo-queries using PostGIS thanks to better indices and materialised views @@ -143,4 +169,66 @@ writing skills. to Phoenix/PostgreSQL - Prepared hybrid deployment with on-premise/in-cloud system - Migrated of the existing deployments from MongoDB to PostgreSQL +- Implemented service to decode Dutch and Belgian postal codes to approximate + geographical locations +{% end %} + +{% section() %} +### Nukomeet - Ruby Developer + +Apr 2015 – Nov 2016 + +- Maintain and expand conference management and ticketing system for conferences + organised by the company {% end %} + +{% section() %} +## Selected Projects + +- **Ultravisor** (Elixir and Rust) — Ultravisor is a scalable, cloud-native + Postgres connection pooler. An Ultravisor cluster is capable of proxying + millions of Postgres end-client connections into a stateful pool of native + Postgres database connections +- **e9p** (Erlang) — Implementation of 9p filesystem protocol in pure Erlang +- **erlang-systemd** (Erlang) — Integration library between Erlang applications + and systemd service descriptions +- **mix_unused** (Elixir) — Mix task and compiler hook that locates unused + public functions in your Elixir projects. +- **dolores** (Rust) - local development proxy with local TLS certificate + generation and dynamic project registration +{% end %} + +## Public Appearances + +### Thinking Elixir Episode 149 - *Elixir's Unified Logger* + +I have talked about my work to unify Erlang and Elixir loggers. History, +troubles, and new features that were added during that work. + +- Thinking Elixir Podcast · May 2023 · Guest + +### "config.exs is Simple" and Other Lies + +Talk about `config.exs` file in Elixir projects showing how compile-time +configuration intermingles with runtime configuration. My approaches to the +handling systems configuration. + +- ElixirConf EU · Jun 2022 · London, UK · Presenter +- Elixir Meetup #2 Curiosum · Feb 2022 · Presenter + +### Who Supervises Supervisors? + +OTP supervisors allow programmers to write reliable software in occurrence of +errors in our code, but what happens when there is a bug in the OTP itself? Or +in cases when our system becomes unresponsive despite the fact that all +processes are up and running. That is where the system supervisor, like systemd, +comes to play to help operations to keep the application up and running while +being able to reliably observe the state of application. + +- Code BEAM V America · Mar 2021 · San Francisco · Presenter · Virtual + +## Languages + +- Polish - native +- English - full professional +- German - elementary -- 2.51.2