Available for new projectsMAR 2026
Backend & Solana
engineering.
I fix production systems that other engineers are afraid to touch. 7 years shipping. Fixed scope. No fluff.
Krzysztof Ziolkowski 🇵🇱
Backend & Blockchain Eng.
Amsterdam, Netherlands
YEARS
7+
STACK
TS / RUST
CHAIN
SOLANA
HACKATHONS
6
Services
CodeServiceStackStatus
One senior engineer. End-to-end ownership. No hand-off to a junior.
Work
raster.finance— Payments Platform / Lead Engineer
Problem
Mission-critical payments platform on inherited, unstable services. Could not rewrite under delivery constraints. Failures hit revenue directly.
Approach
- → End-to-end ownership: payments, backend, infra, security
- → Observability into low-trust codebase
- → Delivery-first trade-offs, controlled tech debt
Result
- → Platform stabilized under production load
- → Delivery timelines met
- → Single escalation point for reliability
NestJSTypeScriptSolanaPostgresKubernetesgRPC
cryptom.app— Solana dApp / Founder & CTO
Built the entire Solana backend from scratch — on-chain programs (Anchor), gasless Node.js services, REST APIs, WebSockets. Shipped to Mainnet. Resolved protocol-level issues directly with Metaplex, Solana, and Circle.
SolanaAnchorTypeScriptNestJSAzurecNFTs
2137.dev— Real-time Solana Trading Infra
Sub-second data streaming pipelines. On-chain/off-chain coordination for latency-sensitive sniper bots. MEV-aware systems with Jito bundler.
RustAnchorgRPC YellowstoneRedisClickHouse
Packages
Fixed scope. Fixed price.
AUD1–2 WK
Audit & Fix
$2,000
- —Codebase audit (backend & infra)
- —Performance bottleneck ID
- —Up to 20h hands-on fixes
- —Written findings & recs
BLD2–4 WK
Build & Ship
$3,500
- —Full feature scoping & architecture
- —Implementation & testing
- —Deployment to your env
- —Schema design if needed
- —Docs & handoff
- —1 week post-deploy support
RES2–4 WK
Rescue & Stabilize
$5,000
- —Emergency system assessment
- —Production stabilization
- —Monitoring & observability
- —Infra hardening
- —On-call during engagement
- —Runbook & handoff docs
Custom scope? Let's talk.
FAQ
Contact
Scope your project
24h response time. No commitment.