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Web3 & Smart Contract Engineer

SEED

Pragmatic security and testable on-chain work

Hourly rate

€125.00/hr

Availability

Project-based

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General

Tags

Web3SolidityEVMSecurityTesting

Description

What this engagement is designed to deliver

This profile summarizes how I work as a software engineer in web3 and smart contracts. I am careful about security and upgrade paths on-chain; I will say no to patterns that are unsafe at your scale. Over the years I have supported organizations that needed audited patterns and testable deployment flows. The sections below follow how I run engagements end to end, from the first working session to production and continuous improvement. Everything here is sample content for demonstration; it is not a reference to any specific client, person, or confidential engagement. I structure work so you can see trade-offs, dependencies, and costs before we commit, and I prefer honest ranges over optimistic promises.

At a glance

  • Primary line — Pragmatic security and testable on-chain work
  • Core skills — Solidity, EVM, Foundry
  • Set-up — remote with a project cadence and 4 years of relevant experience
  • Languages — English for meetings and deliverables

A three-step cadence (typical)

  1. A focused discovery pass — map outcomes, constraints, stakeholders, and the riskiest dependencies.
  2. A thin end-to-end slice first — so integration, delivery, and observability are real, not deck fiction.
  3. A clean handover — playbooks, decisions, and a backlog your team can carry without a prolonged dependency.

“I am careful about security and upgrade paths on-chain; I will say no to patterns that are unsafe at your scale.” — synthetic pull-quote for list 17; not a real client reference.

Demo links & resources: Ways of working (demo), Example artifact pack, Synthetic reading list — all content is fictional and safe for public demos.

Collaboration —.

More on delivery, trade-offs, and continuity

Discovery always starts with constraints: business outcomes, team topology, security posture, and the timeline you are willing to invest in. I run structured workshops that turn vague goals into measurable acceptance criteria, service boundaries, and a backlog that your stakeholders can read without a glossary. I document decisions in a lightweight decision log, link them to your roadmap, and make sure the same context travels into engineering — so scope creep is visible before it is expensive. Where legacy systems are involved, I start with a thin slice that proves integration patterns and de-risks the hardest dependency first. That sequence keeps momentum while protecting production traffic and on-call engineers from unplanned work.

I prefer shipping in thin verticals with observability and rollback baked in. That means feature flags, staged rollouts, synthetic checks, and dashboards that answer whether users are completing the journeys that matter, not just whether the cluster is up. I partner with SRE and security to align on secrets handling, key rotation, dependency scanning, and incident playbooks. When you need a bridge into procurement or compliance, I translate between vendor contracts and the technical work required to deliver them, so you do not pay twice for the same control. I am comfortable in regulated environments: audit trails, least-privilege access, and evidence packs that an external assessor can follow from ticket to production.

Quality is a product decision. I work with you to pick the right test pyramid: contract tests for APIs, targeted end-to-end suites for the highest-risk user journeys, and static analysis in CI to catch the categories of defects that your team is tired of re-opening. I encourage pairing and mobbing when knowledge transfer matters, and I leave your team with scripts, templates, and a definition of done that is enforceable, not aspirational. Performance work follows evidence from traces and budgets rather than pre-emptive rewrites, and I document hotspots with reproduction steps your developers can re-run locally. Accessibility and internationalization are treated as requirements with concrete checks, not late-stage tickets.

The user interface is where your promise meets reality. I combine qualitative insight from interviews and sessions with analytics that show where workarounds and silent drop-offs begin. I translate that into a coherent interaction model, component library usage, and writing patterns for empty states, errors, and long-running operations. I prototype at the right fidelity: sketches when the problem is poorly understood, high-fidelity when alignment between marketing and product is the blocker. I coordinate with brand and content so the tone of voice in the product matches the story you tell on the website, and I prepare engineering handoff that reduces rework on spacing, copy, and motion.

Appendix: extra detail (still synthetic)

Data engineering only matters when the business can trust the numbers. I set expectations around freshness, idempotency, and reconciliation between sources. I am explicit about the difference between a dashboard for day-to-day operations and a dataset for modeling, because mixing them is how organizations ship optimistic forecasts by accident. I have worked with dbt, streaming ingestion, and batch warehouses; I will recommend the mix that fits your data volume, skill mix, and regulatory constraints. I document lineage, ownership, and SLAs, and I build the first set of data quality rules that are painful enough to fail loudly when the pipeline breaks, not months later in a board deck.

I treat APIs as public contracts even when the audience is internal. Versioning, deprecation policy, and error models are part of the first design review, not a retrofit after launch. I favor standards where they exist — OpenAPI, problem+json, OAuth2 patterns — and I document the intentional deviations so future maintainers are not left guessing. For integrations with third parties, I map retry semantics, idempotency keys, webhooks, and data residency expectations up front, using realistic sandbox data before anyone commits a launch date. That discipline reduces the integration surprises that show up in production under customer load.

I approach leadership as a system: clear goals, protected focus time, and a rhythm of reviews that is honest about blockers. I have led mixed seniority groups across time zones, and I structure ceremonies so that distributed teammates have equal access to context. I work with people leads on growth plans, not only tickets, and I am explicit when trade-offs are technical versus organizational. When a programme is in distress, I reset the narrative around outcomes and a minimal recovery path instead of a sweeping rewrite, because morale and momentum often return faster with a small win on the critical path.

About Me

I combine hands-on build work with light-touch facilitation. Small teams get working software quickly; larger programmes get a backbone of architecture and governance that still leaves room to react to learning. I document where money and risk live — integrations, data contracts, and deployment paths — and I avoid cleverness in places that need boring reliability. I have supported migrations, greenfield products, and rescue efforts where the brief was to make the system boring again. I prefer async updates with actionable decisions so meetings stay short.

Category

development

Details

Skills

SolidityEVMFoundryTypeScriptSecurity reviews

Hourly rate

€125.00/hr

Availability

Project-based

Years of Experience

4

Work Mode

Remote only

Languages

English

Location

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Warsaw, Poland

Demo seed

freelancer-explore-v2

May 12, 2026 — sample only, not a real person

Freelancer