Nikita Chernyi

Principal Backend Engineer · Go · Distributed Systems & Federated Protocols PDF

Porto (Matosinhos), Portugal · EU-remote · Valid Portuguese residence permit (EU work authorisation, no sponsorship required)

Contacts

cv@rakshazi.me · LinkedIn (opens in new tab) · github.com/etkecc (opens in new tab) · Matrix (opens in new tab) · etke.cc/blog (opens in new tab)

Summary

Backend engineer, thirteen years in production, nine of them in Go. I design, build, and run distributed systems end to end: protocol work, storage, payments, observability, and the infrastructure underneath. Most of what I put my name to is software I’ve personally shipped and kept running.

etke.cc began as a side project in 2021 and became a bootstrapped company in 2026, with Slavi Pantaleev as cofounder. We’re a team of five running managed Matrix hosting: Cloud Hosting on Hetzner and On-Premises on customer infrastructure, 1,000+ Matrix servers installed across six regions on three continents. I lead engineering and write most of the in-house Go: the automation platform that runs the fleet, the subscription and invoicing stack (Stripe, PayPal, Vendus), the search engine behind MRS / MatrixRooms.info, and Ketesa, our Matrix admin panel. We co-maintain matrix-docker-ansible-deploy and the M.A.S.H. playbook, the automation everything else runs on.

Since 2024 I’ve also worked on Hellotickets’ billing and payments platform. Between the two I stay fluent in two very different operational models: an Ansible-managed Hetzner fleet at etke.cc, and a Kubernetes and GitOps cloud stack at Hellotickets.

My focus is hands-on senior engineering, not management. I keep etke.cc small by design and stay in the code alongside direct IC work, because building is the work I want to be doing. I do my best work where the stack spans protocols, storage, payments, and infrastructure at once, where reliability and operability are first-class concerns, and where the engineering has to answer to the business.

Areas of expertise

Backend Engineering · Distributed Systems · Federated Protocols (Matrix) · Payments & Billing · Infrastructure as Code · Production Operations · AI / LLM Systems · Open-Source Software

Technical stack

Languages. Go (primary, 9+ years in production). TypeScript, Python, PHP, and Bash are occasional: comfortable reading and writing smaller pieces, not daily drivers. Backend. Go (Echo, mautrix-go, Bleve) · PostgreSQL, SQLite, Valkey · BoltDB for embedded stores · ElasticSearch · gRPC. Infrastructure & operations. Ansible, Docker, Hetzner Cloud, AWS, Azure, GCP, Kubernetes, Helm, ArgoCD, Terraform, Traefik · Prometheus, VictoriaMetrics, Grafana · GitLab CI, GitHub Actions, Jenkins. Payments & billing. Stripe, PayPal, NetSuite, payment-orchestration platforms, Vendus. AI / LLM systems. Practical LLM application engineering: model-curated memory, retrieval (FTS5/BM25), context compaction and summarisation, tool-use orchestration, and prompt-injection defence. Operations support. Sentry, Postmark, Redmine, FreeScout. Protocols. Matrix federation, SMTP, gRPC.

Work Experience

2021 – Present · Principal Backend Engineer & Founder · etke.cc (opens in new tab)

Remote · Portugal

etke.cc is a managed Matrix hosting service. A customer gets a dedicated, federated Matrix homeserver with their chosen bridges, clients, bots, and moderation tooling, and we run the whole thing end to end as a distributed system across multiple regions. I started it as a side project in 2021; it became a bootstrapped company in 2026, with Slavi Pantaleev as cofounder. We’re five now: four engineers and an administrator covering invoicing and accounting. No outside funding. I lead engineering and write the majority of the in-house Go microservices.

• Scale. 1,000+ Matrix servers installed across six Hetzner regions on three continents (two in Germany, plus Finland, two in the United States, and Singapore), with On-Premises deployments running on customers’ own infrastructure.
• Service catalogue. Cloud Hosting on Hetzner Cloud, On-Premises on customer hardware or cloud, and bundled Monitoring. A Private Docker Registry fronts the fleet: our open-source docker-registry-proxy (opens in new tab) caches upstream images so a public-registry outage never stalls a deployment. Custom Development is billed hourly at €150, every line released under GPL/AGPL back into the original open-source project.
• Fleet automation. I wrote the Go services that run the customer fleet: maintenance automation and scheduling, subscription lifecycle, service discovery, fleet monitoring, and remote-configuration tooling. All in production.
• Fleet-wide secrets-at-rest. Designed and built the encryption layer that keeps customer secrets out of plaintext across our internal infrastructure. Secrets are encrypted in memory the moment an order is created, so cleartext credentials never touch disk. A small AES-GCM primitive (go-kit/crypter) with a self-describing, versioned ciphertext format underpins field-level and whole-file encryption throughout the Ansible inventory: admin and database passwords, Synapse secrets, S3 keys, DKIM private keys, Borg backup passphrases. Operators seal values through a CLI and an internal, deliberately decrypt-less web tool; seven fleet services then decrypt transparently at point-of-use. There is no decryption path on the ingest side by design, since one would be an oracle holding the inventory key behind a single login.
• Subscription and invoicing. Built the billing backend end to end. Stripe and PayPal come in through webhooks as the near-real-time source of truth, with scheduled API reconciliation as a safety net against missed or delayed events. PDF invoice generation via Vendus, inbound-email and bounce handling, outbox-pattern notifications, and an internal operations UI. The 2026 company incorporation shipped alongside Stripe card payments and a full migration to EUR billing.
• Matrix federation search. MRS is the open-source federated public-room search engine I built in Go (Echo, Bleve, BoltDB). It indexes the public Matrix federation every day, thousands of servers and rooms, without ever joining a room or touching user data, and it doubles as a trusted Matrix notary key server. It implements MSC1929, MSC3266, MSC4121, MSC4265, and MSC4439. MatrixRooms.info (opens in new tab), the reference instance etke.cc runs, is relied on across the Matrix ecosystem.
• Ketesa (opens in new tab). Our Matrix homeserver admin panel. It started in August 2024 as a fork of Awesome-Technologies/synapse-admin; by April 2026 we’d rebuilt it end to end and released it as an independent product (v1.0.0). Mobile-first UI, ten fully-translated languages, full Matrix Authentication Service integration, drop-in auto-configuration via /.well-known/matrix/client. It ships through many channels: official releases, GHCR, Docker Hub, matrix-docker-ansible-deploy, etkecc/ansible, Nixpkgs, YunoHost (opens in new tab), Arch AUR, and IPFS. For etke.cc customers it doubles as the control plane: live server status, scheduled maintenance, in-panel billing, and an in-app ticketing system.
• Matrix-native services. A family of Go bots and bridges I authored for the platform. The two most-used: honoroit, a helpdesk bot that threads encrypted one-to-one conversations into back-office ticketing rooms, and postmoogle, a full SMTP↔Matrix bridge with DKIM, SPF, DMARC, and per-mailbox encryption. Alongside them, buscarron (web forms into Matrix), baibot (a conversational-AI bot), emm (message export), ttm (a time-like CLI that reports into Matrix), and smaller tooling like inventory-ssh. The customer-facing ones ship in matrix-docker-ansible-deploy.
• Infrastructure automation. I co-maintain matrix-docker-ansible-deploy (opens in new tab) with Slavi, the core of etke.cc’s automation and the most widely-used community Matrix self-hosting playbook. Several of our in-house components ship in it by default, and its README names etke.cc as the recommended managed hosting option built on it. I also co-maintain the M.A.S.H. playbook (opens in new tab), the next iteration of our infrastructure automation, and I’m a significant contributor to the Ansible role catalogue underneath both.
• Go libraries. Several reusable Go libraries consumed across the etke.cc stack. The most-used are go-kit (opens in new tab) (shared utilities, including the crypter encryption primitive above), go-linkpearl (opens in new tab) (a mautrix-go bot toolkit with zero-config E2E encryption), and go-ansible (opens in new tab) (an Ansible inventory parser). All under github.com/etkecc (opens in new tab).
• Operations. Replaced the old dual-channel release cadence with rolling releases, fronted by pre-deployment test stands that run the playbook against disposable hosts before any customer sees it. Standardised on IPv6, HTTP/3, Traefik, Unix-socket PostgreSQL and Valkey, and Prometheus + VictoriaMetrics + Grafana for observability.

2024 – Present · Go Developer, Billing · Hellotickets (opens in new tab)

Remote

Hellotickets is an international live-events ticket marketplace, operating on a company-wide four-day work week. I work on the billing and payments platform.

• Owned the reliability of the internal payments service: rewrote failure-handling and reconciliation paths, converting a standing backlog of failed transactions into recovered revenue and reducing ongoing leakage.
• Core contributor to the migration of Hellotickets’ payments onto a new payment-orchestration platform, unlocking additional payment methods and enabling a local-first checkout experience across several international markets.
• Designed the currency and payment-method A/B testing setup end to end, giving the business a controllable lever on checkout conversion and cross-market revenue.
• Shipped the GDPR redaction and user-removal system.
• Built the NetSuite invoice synchronisation powering customer invoicing.
• Built the disputes synchronisation and its integration into the customer-experience and back-office systems.

2021 – 2023 · Senior Software Engineer · Crunchyroll (opens in new tab)

Remote · Chișinău, Moldova

Backend work across content discovery, search, and the home page at Crunchyroll’s scale: millions of requests per minute. On a team of five, including the engineering manager.

• Stabilised ElasticSearch on the core search and content-discovery path through horizontal scaling and an ingestion redesign.
• Integrated Sony Music’s catalogue into content discovery and search.
• Shipped dub-rendition support, real-time personalised recommendations, and A/B-testing integration on the content-discovery path.
• Built the backend for the Home Page, directly improving engagement and navigation.
• Reworked backend caching, cutting server count and cost while raising throughput.
• Led CI migrations, linter adoption, and routine vulnerability scanning across backend services.
• Shipped Discord Rich Presence integration.

Earlier Experience (2013 – 2021)

2017 – 2021 · Senior Backend Developer & DevOps · Titanium Software (Chișinău, Moldova). Lead engineer and DevOps across five client projects. Drove the company’s adoption of Infrastructure-as-Code and a DevOps operating model. Notable work: Tpoint (squash-court IoT and booking platform), 2CB (B2B voice-automation portal), an industrial IoT project on Azure and AWS (Kubernetes, Couchbase, ElasticSearch), SportsWith (events platform on PHP 7.1 / Slim), MathodiX, fone.do.

2014 – 2017 · Backend Developer & DevOps · OpsWay (Remote). Magento e-commerce work. Authored 10+ production extensions; Ansible-managed dockerised deployments; flagship Antoshka.ua.

2013 – 2014 · Support Engineer · Active Computers (Tiraspol, Moldova). Web support and in-house tooling.

Selected Open-Source Projects

The full catalogue lives at github.com/etkecc (opens in new tab).

• MRS / MatrixRooms.info (opens in new tab) — federated public-room search engine in Go (Echo, Bleve, BoltDB) that crawls the Matrix federation without joining rooms.
• Ketesa (opens in new tab) — Matrix homeserver admin panel: mobile-first, ten languages, full Matrix Authentication Service integration, packaged everywhere from GHCR to Nixpkgs, YunoHost, and the AUR.
• matrix-docker-ansible-deploy (opens in new tab) — the core of etke.cc’s automation and the most widely-used community Matrix self-hosting playbook, co-maintained with Slavi Pantaleev.
• M.A.S.H. playbook (opens in new tab) — next-iteration self-hosting automation, co-maintained with the etke.cc team.
• honoroit (opens in new tab) — Matrix helpdesk bot with E2E-encrypted rooms and ticketing.
• postmoogle (opens in new tab) — bidirectional SMTP ↔ Matrix bridge with DKIM, SPF, DMARC.
• A.G.R.U. (opens in new tab) — git-native replacement for ansible-galaxy, used in matrix-docker-ansible-deploy and across etke.cc.
• docker-registry-proxy (opens in new tab) — caching Docker Registry proxy behind our Private Docker Registry service.
• go-kit (opens in new tab) · go-linkpearl (opens in new tab) · go-ansible (opens in new tab) — the three most-used Go libraries across the etke.cc stack. go-kit carries the crypter AES-GCM encryption primitive behind the secrets-at-rest pipeline.

References

“Nikita is a good backend developer and DevOps engineer who is not afraid to jump into learning about new protocols and technologies. His work on etke.cc (and not only) demonstrates that he is capable of taking a problem and building a solution which spans the whole stack — business requirements, frontend and backend development, production deployment, and customer support.”

— Slavi Pantaleev, Cofounder, etke.cc · Maintainer, matrix-docker-ansible-deploy

“Strong and passionate backend engineer with lots of focus on improving the performance and healthy state of the services he is working on. At Crunchyroll his focus was on building stable, scalable, and performant backend services handling millions of requests per minute — optimising not only how they perform but also how costly they are. He likes to delve into Go’s architecture so the team uses the language to its full capability.”

— Vlad Ledniov, Engineering Manager, Crunchyroll

Languages

• English — Fluent
• Russian — Native
• Portuguese — Learning