01 / Selected work

Systems that
hold under load.

The decisions, constraints and measured outcomes behind projects in enterprise RAG, webhook infrastructure, streaming and financial analytics.

01

Enterprise RAG

2026 — Present

Interim Robots

Solo build · Live

interimrobots.pl

An answer is only useful when you can trace where it came from.

Enterprise RAG platform for internal company procedures (1k–10k documents per deployment) — single-tenant, on-premise or customer-cloud, with an optional fully self-hosted LLM so no document ever leaves customer infrastructure.

Hybrid retrieval pipeline: pgvector cosine search + PostgreSQL full-text search fused via RRF, then cross-encoder reranking — p95 retrieval latency ≤ 700 ms before the LLM call. Every answer cites source document and page; insufficient context returns an explicit refusal instead of a hallucination.

Security-first architecture: department isolation enforced by Postgres Row-Level Security (not application code), ACL filtering before any content reaches the model, and an append-only audit log (no UPDATE/DELETE path) designed for EU AI Act Art. 12 logging requirements, plus prompt-injection hardening.

Built a deterministic synthetic Polish eval corpus (107 documents, 94 golden test cases including injection canaries) for regression testing of retrieval quality.

  • p95 retrieval ≤ 700 ms
  • Postgres RLS + ACL
  • EU AI Act Art. 12 audit log
  • 94 golden test cases
PythonFastAPIPostgreSQL + pgvector (RLS)RedisNext.js 16Claude via AWS Bedrock (EU)DoclingDockerTerraform
02

Webhook infrastructure

2025 — Present

HookSync

Solo build · Live

hooksync.net

Events delivered reliably — even when the receiver refuses to cooperate.

Multi-tenant webhook delivery SaaS in Rust — reliable event delivery with HMAC-SHA256 payload signing, exponential-backoff retries and dead-letter queues; sub-10 ms enqueue latency on the hot path.

Full production surface: tenant isolation, Stripe subscription billing, a delivery observability dashboard (Next.js) and idempotent delivery semantics.

  • Enqueue < 10 ms
  • Idempotent delivery
  • HMAC-SHA256 signing
  • Tenant isolation
Rust (Axum)PostgreSQLRedisNext.js 16StripeAWSTerraform
03

OTT streaming

2025 — Present

Tivod

Solo build · Beta

tivod.online

One of the few production attempts at a full-Rust web stack.

Full-stack OTT streaming platform — an architectural evolution of a prior PPV system, rebuilt entirely in Rust on both frontend and backend.

Backend: Rust + Axum for the API and streaming coordination layer. Frontend: Rust + Leptos (WASM) with Tailwind CSS.

Infrastructure: AWS with an Application Load Balancer, S3 for media storage and Lambda for event-driven tasks. Currently in closed beta.

  • Rust end to end
  • WASM frontend (Leptos)
  • AWS media pipeline
  • Infrastructure as code
Rust (Axum, Leptos)Tailwind CSSAWS (ALB, S3, Lambda, EC2)Terraform
04

PPV streaming

2025

Fightime.tv

Solo build

A pay-per-view platform shipped from scratch — ingest to checkout.

PPV video streaming platform built from scratch in Rust + Next.js on AWS: ingest pipeline, authentication, payment integration and CDN delivery.

Owned the full lifecycle — architecture, stream ingest, auth and payments — on EC2, S3, CloudFront and RDS.

  • Rust (Axum) backend
  • Full ingest pipeline
  • Payments + auth
  • CloudFront delivery
Rust (Axum)Next.js 16AWS (EC2, S3, CloudFront, RDS)
05

Financial analytics SaaS

2025

VerifyStock

Solo build

Real-time market data, billing and multi-tenant isolation in one product.

Financial analytics SaaS with real-time data feeds, Stripe billing, Supabase and multi-region AWS deployment.

Implemented subscription management, real-time data sync and multi-tenant data isolation.

  • Real-time data sync
  • Stripe billing
  • Multi-tenant isolation
  • Multi-region AWS
Next.jsSupabaseStripeNode.jsLambdaEC2Redis
06

Open source

Ongoing

rustbackendstarter

github.com/kezzlock

github.com/kezzlock

A production-ready Rust backend template, not a toy scaffold.

Axum + SQLx + PostgreSQL foundation with JWT auth (HS256), Argon2id password hashing, utoipa/Swagger documentation and Docker Compose for local parity.

  • JWT (HS256) auth
  • Argon2id hashing
  • OpenAPI docs
  • Docker Compose
RustAxumSQLxPostgreSQLutoipaDocker Compose