Johan Visser
Aldershot,Hampshire
Summary
Proficient in C#, .NET, SQL Server, and Oracle, with a proven history of transforming legacy systems into scalable, maintainable, and performance-driven solutions.
Offering strong background in problem-solving, collaboration, and adapting to new technologies. Knowledgeable about software development principles and eager to apply coding and analytical skills in team setting. Ready to use and develop programming, teamwork, and project management skills.
Overview
29
29
years of professional experience
2
2
years of post-secondary education
1
1
Certification
Work history
Senior software developer
H&T Pawnbrokers
Sutton, City of London
2018.06 - 2025.09
- Assisted in designing and maintaining enterprise-grade C# / WPF applications using MVVM architecture pattern for loan origination renewals and customer account servicing.
- Supported operational consistency through improved software solutions.
- Contributed to SQL Server development tasks such as query refactoring and index optimisation.
- Helped reduce reporting runtime significantly, improving efficiency for management decision cycles.
Software Developer
Iress
Leatherhead, Surrey
2016.11 - 2018.05
- Assisted in building and enhancing C# / WPF reporting and workflow management tools for finance teams to consolidate data, visualise monthly performance, and streamline reporting tasks previously performed via spreadsheets or manual extraction.
- Restructured and indexed Oracle database tables, views, and stored procedures to aid in improving data retrieval efficiency, contributing to faster month-end financial close process.
- Supported diagnosis and resolution of recurring reporting latency, application data mismatches, and system stability issues through performance profiling and error investigation.
Senior Developer & Assistant Scrum Master
Centric
Gouda, Netherlands
2000.01 - 2016.11
- Assisted in modernising desktop applications by migrating Delphi solutions to C# WinForms.
- Supported modular architecture implementation, contributing to 35% reduction in maintenance costs.
- Helped enhance data reliability and performance across Oracle and SQL Server by refining data models and validation rules, leading to 20% decrease in data integrity issues.
- Facilitated agile processes as assistant Scrum Master, aiding in sprint planning and stand-ups, resulting in 15% improvement in delivery predictability.
- Optimised reporting capabilities by improving Crystal Reports, reducing analyst workloads by 25%.
Software developer
ESSENTIUM
Rotterdam, Netherlands
1996.06 - 2000.01
- Assisted in designing, coding, and maintaining Delphi-based applications that support administrative and financial tasks.
- Facilitated data integrity through introduction of validation routines and improved exception handling.
- Collaborated with team members to gather requirements and respond to support requests effectively.
- Worked with internal tools to create callcenter software ahead of time and under budget.
Education
AMBI 1 & 2 - General IT
EXIN
Netherlands 1998.02 - 1998.08
Diploma in Computer Science - General IT
Ecabo
Netherlands 1995.02 - 1995.09
Diploma PDI 1 & PDI 2 - General IT
PDI 1 & 2
Netherlands 1994.03 - 1995.03
Skills
- C# and NET development
- WPF and WinForms applications
- Delphi programming
- SQL Server optimization
- Oracle PL/SQL optimization
- Legacy systems modernization
- Agile and Scrum methodologies
- Debugging and analysis
- Version control systems
Certification
Microsoft Certified Azure Fundamentals — Microsoft, February 2023
Scrum Fundamentals Certified — SCRUMstudy, June 2020
Certificate in English for Presentations — Liguarama, 2016
Certificate in Security for Developers — Centric IT Solutions, 2015
Certificate in Mastering Object Oriented Programming with SQLWindows — Centura Software Corporation, 2001
Certificate in Oracle DBA — Essentium Educational Services, 2000
Certificate in Oracle Designer/2000: Forms Design and Generation — Oracle, 1999
Languages
English
Fluent
Dutch
Native
Timeline
Senior software developer
H&T Pawnbrokers
2018.06 - 2025.09
Software Developer
Iress
2016.11 - 2018.05
Senior Developer & Assistant Scrum Master
Centric
2000.01 - 2016.11
AMBI 1 & 2 - General IT
EXIN
1998.02 - 1998.08
Software developer
ESSENTIUM
1996.06 - 2000.01
Diploma in Computer Science - General IT
Ecabo
1995.02 - 1995.09
Diploma PDI 1 & PDI 2 - General IT
PDI 1 & 2
1994.03 - 1995.03