Complex problem resolution
The toughest bugs — intermittent, architectural, multi-system — are identified and fixed where standard approaches have failed.
Debugging & bug fixing Your most complex technical problems identified, fixed and stabilised for the long term
When standard fixes are not enough, our team carries out an in-depth root cause analysis of your toughest bugs — websites, software, servers, databases. Lasting resolution, stabilised systems and full documentation to prevent any recurrence.
Root cause analysis — no superficial fixes
Thorough testing before any deployment
Full documentation — zero recurrence
What you get
Complex problems resolved for the long term
Your most complex bugs are identified at the root and fixed permanently — systems stabilised, documentation provided, recurrence avoided.
100%
root causes found
–95%
recurrence rate
Expert
senior intervention
A complex bug not resolved at the root returns on average 4 times before being properly addressed — costing 4× more than an initial in-depth analysis
Complementary maintenance services
Corrective maintenance
Rapid fixes for common bugs and standard anomalies — for well-identified problems.
Outsourced technical support
Day-to-day assistance for your teams — answering questions and resolving common problems.
Managed services & hosting
Proactive management of your infrastructure to prevent problems before they become critical.
Scope of intervention
What types of complex bugs do we work on?
From intermittent bugs that are impossible to reproduce to critical problems that paralyse your business — our team handles the toughest cases, across all types of systems.
Complex website bugs
Intermittent display issues, JavaScript conflicts, bugs linked to corrupted caches, cross-browser compatibility problems, 500 errors with no clear message.
Application & software bugs
Complex business logic errors, bugs reproduced only in production, problems linked to migrations, conflicts between modules or dependencies, memory leaks.
Server & infrastructure problems
Intermittent server crashes, performance issues under load, configuration errors, conflicts between services, DNS or network problems.
Database corruption & anomalies
Corrupted or inconsistent data, slow queries with no explanation, database locks, replication problems, partial data loss and restoration.
Security vulnerabilities & intrusions
Post-hack analysis, attack vector identification, malware cleanup, closing exploited vulnerabilities and access hardening to prevent recurrence.
Performance degradation
Application or site suddenly slow with no apparent reason — profiling, bottleneck identification, targeted optimisation and post-intervention monitoring.
Our approach
How do we resolve complex bugs?
A rigorous investigation process — from initial analysis to final documentation — to ensure the problem is resolved at the root and will not return.
In-depth analysis
Collection of all available information: logs, context, reproduction conditions, change history and technical environment
Root cause investigation
Methodical root cause analysis — we do not stop at the symptom, we trace back to the deep source of the problem for a definitive fix
Advanced diagnosis
Use of profiling, monitoring, debugging and advanced log analysis tools to pinpoint exactly where the problem originates
Precise technical fix
Development of the fix in an isolated environment — surgical intervention on code, configuration or infrastructure without side effects
Thorough testing
Exhaustive test suite to validate the fix and ensure no side effects — functional, load and regression testing
System stabilisation
Intervention on adjacent systems that may have been weakened by the bug or the fix — to guarantee overall stability
Complex environment intervention
Ability to work on complex architectures — microservices, multi-environment setups, legacy systems, hybrid infrastructures
Full documentation
Detailed bug report: root cause identified, fix applied, tests carried out and recommendations to prevent any recurrence
What it changes
What you gain from expert debugging
Fixing a bug superficially costs less in the short term — but on average costs 4 times more in the long run. Expert debugging resolves the problem once and for all.
System stabilisation
Beyond the fix, your systems are stabilised — adjacent weaknesses identified and addressed to guarantee lasting reliability.
Risk reduction
A complex bug not treated at the root is a permanent risk. A definitive fix eliminates that risk and protects business continuity.
Improved reliability
Every complex bug resolved improves the overall robustness of your system — your tools become progressively more reliable and predictable.
Expert intervention
Senior developers specialising in complex debugging — experience across hundreds of different architectures, knowledge of recurring bug patterns.
Project variables
What determines the budget for a debugging mission
The cost of debugging depends mainly on the complexity of the problem and the criticality of the system. We provide an estimate after the preliminary analysis, with no hidden fees.
Problem complexity
Isolated, reproducible bug to intermittent bug not reproducible in a controlled environment
Type of system
WordPress site to bespoke application with microservices architecture and multiple dependencies
Criticality level
Minor bug (slight degradation) to critical bug (complete business shutdown or data loss)
Urgency
Planned resolution to emergency intervention requiring immediate team mobilisation
Technologies used
Standard technologies (PHP, JS) to highly specific or legacy stack requiring rare expertise
System access
Full access to logs and environments to restricted access or production systems that cannot be stopped
Problem history
Recent problem with clear history to long-standing bug with no logs or documentation available
Security level
Standard system to highly secure environment with specific access and confidentiality constraints
Our pricing
How much does a debugging mission cost?
Pricing is estimated after preliminary analysis of the problem. Transparent quote before commitment, with no hidden investigation fees.
Simple debugging
€300 – 1,000 excl. VAT
Identifiable bug and targeted fix
- Problem analysis
- Targeted fix
- Functional testing
- Resolution documentation
Most common
Complex debugging
€1,000 – 3,000 excl. VAT
In-depth root cause analysis
- Full root cause analysis
- Advanced diagnosis (logs, profiling)
- Fix & thorough testing
- System stabilisation
- Full report & recommendations
Critical debugging
€3,000 – 10,000 excl. VAT+
Emergency, security, complex systems
- Emergency mobilisation
- Dedicated senior team
- Complex environments (legacy, security)
- Data restoration if required
- Post-mortem & prevention plan
For common bugs and rapid fixes, see our corrective maintenance service (€150–1,500). A full maintenance contract includes a priority debugging budget.
What is the difference between debugging and corrective maintenance?
Corrective maintenance handles common bugs with rapid fixes. Debugging tackles complex problems that are hard to reproduce or have high impact, requiring in-depth root cause analysis, expert diagnosis and methodical investigation over several days.
How long does a debugging mission take?
A simple debugging mission is typically resolved in 1 to 3 days. A complex debugging mission (intermittent bug, architectural problem) often requires 1 to 2 weeks. A critical debugging mission on complex infrastructure can take several weeks. We provide a precise estimate after the preliminary analysis.
What types of bugs do you resolve?
We work on all complex bugs: intermittent bugs that are hard to reproduce, degraded performance problems, conflicts between systems, critical production errors, data corruption, exploited security vulnerabilities, bugs linked to migrations and any problem resistant to standard fixes.
Can you intervene in an emergency?
Yes, we offer emergency interventions for critical bugs paralysing business operations. Contact us directly by phone for a rapid urgency assessment. Critical debugging includes priority mobilisation of the senior team at the earliest opportunity.
How can complex bugs be avoided in future?
Every debugging mission includes a report with prevention recommendations. For proactive protection, managed services with active monitoring detect anomalies before they become critical bugs. A full maintenance contract also includes a priority debugging budget.
A complex bug that will not go away? Our experts find and fix it at the root.
Describe your technical problem — our team will qualify the intervention and provide an estimate within 4 business hours.
Submit my complex bug
Free estimate
Quote before commitment
Resolution report provided