You're seeing this page as if you were . The main menu is still yours, though. Exit from immersion
Malt Strategy
New report
Malt Tech Trends 2026
Sebastián VansteenkisteSV

Sebastián Vansteenkiste

Fullstack Lead Developer

€312/day
Barcelona, ES
8-15 years
.NET
Python
Ownership
SQL
JavaScript

Average response time: 1 hour

Freelancer profile translated to English.
Back to original language

About Sebastián

Hello! I'm Sebastián, a full-stack software developer with 12 years of experience. I offer full responsibility, both for leading projects from idea to final product and for modernizing legacy projects. I can handle the entire process end-to-end: from formalizing the idea into requirements and deliverables, planning it, developing it, testing it, deploying it, and providing support once it's in production. I can work autonomously, as part of a team, or lead a development team as needed for the project.
Consulting and Audits
Health and Wellness

  • Spanish

    Native or bilingual

  • English

    Native or bilingual

  • Japanese

    Conversational

  • Catalan

    Basic

Can work on-site
Barcelona (up to 50km)

Experience

  • Hitachi Energy
    Engineering Manager / Team Lead
    ENERGY AND UTILITIES
    September 2024 - December 2025 (1 year and 3 months)
    Barcelona, Spain
    Led a distributed, multicultural team of 10 developers managing the Digital Passport System (DPS), a global component-traceability platform for high-voltage products with data integrations with manufacturing execution systems (MES). Acted as a "hands-on manager" bridging the gap between business strategy and complex technical execution.
    • • Technical Stewardship: Navigated a highly complex legacy environment (2,000+ line stored procedures, deep technical debt) by performing technical prospecting and feasibility studies for all new feature requests.
    • • Engineering Quality: Drove system reliability through deep code reviews and architectural unblocking, ensuring developers across Spain, India, and Ukraine maintained standards despite significant performance constraints.
    • • People Leadership: Served as Line Manager for the Spain-based cohort, leading technical hiring, 1:1s, performance reviews, and conflict resolution with a focus on empathy and professional growth.
    • • Process Evolution: Established and documented foundational development workflows and release practices, successfully reducing meeting overhead and improving transparency between Product and Engineering.
    • • Strategic Advocacy: Collaborated with global stakeholders to align priorities, advocating for long-term stability and performance improvements over feature-heavy backlogs in a mission-critical production environment.
    SQL Leadership .NET Strategic planning Microsoft Azure
  • KopiusTech → HCHB
    Senior Full-Stack Developer (.NET / Blazor)
    HEALTH AND WELLNESS
    April 2023 - July 2024 (1 year and 3 months)
    Rosario, Argentina
    Architected and developed core modules for a Blazor + Piral micro-frontend application, modernizing a legacy WinForms-over-Citrix system for a major US healthcare provider (HCHB). Acted as a technical anchor and interim lead for "The Terminators" (web scheduler) team in charge of "eliminating Citrix" from the stack.
    • • Technical Innovation: provided and documented a method to run the entire application stack locally, enabling end-to-end debugging and drastically reducing resolution time for complex issues.
    • • Modernization Strategy: Led the transition from a slow, Citrix-based legacy environment to a high-performance micro-frontend architecture, solving critical user experience bottlenecks like boot-up slowness and lack of SSO.
    • • Architectural Advocacy: Navigated a fragmented technical landscape (GraphQL, custom ORMs, and deep SQL logic) to advocate for and implement unified data-access patterns across teams.
    • • Collaborative Leadership: Stepped in as interim lead to represent the team in high-level architectural and business discussions, bridging gaps between BAs, designers, and mobile/infrastructure teams.
    • • Mentorship: Shared expertise through technical screening and a webinar ("Blazor: Straight to the meat"), fostering technical excellence across the distributed organization.
    SQL .NET Blazor Micro Frontend Teaching
  • Svitla → ASA Financial
    Senior Backend Developer (.NET / Azure)
    BANKING AND INSURANCE
    July 2022 - March 2023 (8 months)
    Rosario, Argentina
    • • Built serverless Azure Functions integrating third-party financial systems; standardized API interfaces across solutions.
    • • Documented existing architecture and business logic, reducing onboarding friction and surfacing improvement areas.
    .NET Microsoft Azure ASP.NET MVC Security C#
Check out Sebastián's experience

Recommendations

Be the first to recommend Sebastián

Help this freelancer shine by sharing your experience working together.

These freelancer profiles also match your criteria

AgathaA

Agatha Frydrych

Backend Java Software Engineer

4.7

(3)

2

BaptisteB

Baptiste Duhen

Fullstack developer

4.6

(4)

5

AmedA

Amed Hamou

Senior Lead Developer

4

(2)

7

AudreyA

Audrey Champion

Web developer

4.3

(3)

4

Signup to reveal

Education

  • Information Systems Engineering
    Universidad Tecnológica Nacional
    2013
    Information Systems Engineering
  • Personal & Professional Computing Technician
    Complejo Educativo Dr. Francisco de Gurruchaga
    2005
    Personal & Professional Computing Technician

Categories