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Bug Fixing & Performance Optimization: Make Your Software Fast and Reliable


Bug Fixing & Performance Optimization: Make Your Software Fast and Reliable

Every software team faces bugs and performance issues. But there’s a huge difference between teams that firefight constantly and teams that systematically eliminate problems. The difference isn’t luck—it’s expertise, methodology, and the right approach to debugging and optimization.

At Async Squad Labs, we specialize in diving deep into complex systems to find and fix the issues that are slowing you down. Whether it’s a critical production bug, mysterious performance degradation, or accumulated technical debt, we have the expertise to diagnose and resolve even the toughest problems.

Why Bug Fixing & Optimization Matter

The Cost of Bugs

Software bugs have real business consequences:

  • Revenue Loss: Downtime costs companies an average of $5,600 per minute
  • Customer Churn: 88% of users won’t return to an app after a bad experience
  • Reputation Damage: One critical bug can undo months of marketing
  • Development Slowdown: Teams spend 42% of time on maintenance and bug fixes
  • Opportunity Cost: Time spent firefighting can’t be spent on innovation

The Impact of Poor Performance

Slow software drives users away:

  • User Expectations: 53% of mobile users abandon sites that take over 3 seconds to load
  • Conversion Impact: Every 100ms delay reduces conversions by 1%
  • SEO Penalties: Google ranks slow sites lower
  • Resource Costs: Inefficient code wastes server resources and money
  • Competitive Disadvantage: Users choose faster alternatives

Our Bug Fixing Services

Critical Bug Resolution

When production is broken, we act fast:

Emergency Response

  • Available for critical incidents
  • Rapid triage and diagnosis
  • Root cause analysis
  • Immediate mitigation
  • Long-term fix implementation

Our Process

  1. Stabilize: Stop the bleeding with immediate workaround
  2. Investigate: Deep dive to find root cause
  3. Fix: Implement proper solution
  4. Test: Comprehensive testing to prevent regression
  5. Document: Share learnings to prevent recurrence

Typical Resolution Times

  • Critical production issues: Hours
  • High-priority bugs: 1-2 days
  • Standard bugs: 2-5 days
  • Complex system issues: 1-2 weeks

Systematic Bug Hunting

Find bugs before your users do:

Proactive Bug Discovery

  • Code review to identify potential issues
  • Static analysis to catch common mistakes
  • Security vulnerability scanning
  • Performance profiling
  • Edge case testing

Bug Prevention

  • Implement better error handling
  • Add defensive programming
  • Create comprehensive tests
  • Improve monitoring and alerting
  • Document failure modes

Legacy Code Bug Fixes

Working with old codebases:

Challenges

  • No tests or documentation
  • Original developers long gone
  • Unclear business logic
  • Outdated dependencies
  • Undocumented behaviors

Our Approach

  • Careful code archaeology
  • Add characterization tests
  • Document current behavior
  • Incremental improvements
  • Risk-aware changes

Intermittent Bug Resolution

The hardest bugs to fix:

Common Intermittent Issues

  • Race conditions and timing bugs
  • Memory leaks and resource exhaustion
  • Network-dependent failures
  • Environment-specific issues
  • Concurrency problems

Our Methodology

  • Reproduce consistently
  • Add comprehensive logging
  • Use debugging tools and profilers
  • Statistical analysis of patterns
  • Systematic hypothesis testing

Performance Optimization Services

Application Performance Optimization

Make your app blazingly fast:

Backend Optimization

  • Database query optimization
  • Caching strategies (Redis, Memcached)
  • API response time improvement
  • Resource pooling and connection management
  • Algorithmic improvements

Frontend Optimization

  • Bundle size reduction
  • Code splitting and lazy loading
  • Image optimization
  • Critical CSS and resource hints
  • Service workers and caching

Full-Stack Optimization

  • Reduce API round trips
  • Implement efficient data structures
  • Minimize payload sizes
  • Optimize render paths
  • Progressive enhancement

Database Performance Tuning

Databases are often the bottleneck:

Query Optimization

  • Identify slow queries with profiling
  • Add appropriate indexes
  • Rewrite inefficient queries
  • Implement query caching
  • Optimize joins and subqueries

Schema Optimization

  • Normalize or denormalize as appropriate
  • Partition large tables
  • Archive old data
  • Implement materialized views
  • Optimize data types

Infrastructure Optimization

  • Connection pooling
  • Read replicas for scaling
  • Database caching layers
  • Vertical and horizontal scaling
  • Monitoring and alerting

API Performance Improvement

Speed up your APIs:

Request Optimization

  • Reduce payload sizes (GraphQL, field selection)
  • Implement pagination and limits
  • Add response compression
  • Batch related requests
  • Use HTTP/2 or HTTP/3

Response Time Reduction

  • Implement caching (CDN, application, database)
  • Add database query optimization
  • Use async processing for slow operations
  • Implement rate limiting and throttling
  • Optimize serialization

Infrastructure Optimization

Right-size and optimize your infrastructure:

Cloud Cost Optimization

  • Identify over-provisioned resources
  • Implement auto-scaling
  • Use spot instances appropriately
  • Optimize storage tiers
  • Review and optimize data transfer

Resource Utilization

  • CPU and memory profiling
  • Identify bottlenecks
  • Optimize resource allocation
  • Implement efficient scheduling
  • Monitor and alert on usage

Load Time Optimization

Every millisecond counts:

Measurement

  • Real User Monitoring (RUM)
  • Synthetic monitoring
  • Lighthouse audits
  • WebPageTest analysis
  • Core Web Vitals tracking

Optimization Techniques

  • CDN for static assets
  • Image optimization and lazy loading
  • Code splitting and tree shaking
  • Minification and compression
  • Critical path optimization

Our Debugging Methodology

1. Reproduce the Issue

You can’t fix what you can’t reproduce:

Reproduction Steps

  • Gather detailed bug reports
  • Identify environmental factors
  • Create minimal reproduction case
  • Automate reproduction when possible
  • Document reproduction steps

For Intermittent Issues

  • Collect statistical data
  • Identify patterns and correlations
  • Test hypotheses systematically
  • Use debugging tools continuously
  • Implement enhanced logging

2. Isolate the Problem

Narrow down the search space:

Techniques

  • Binary search through code paths
  • Disable features systematically
  • Test with minimal configuration
  • Use debuggers and breakpoints
  • Add strategic logging

Tools

  • Debuggers (pdb, Chrome DevTools, dlv)
  • Profilers (py-spy, perf, pprof)
  • Distributed tracing (Jaeger, Zipkin)
  • APM tools (DataDog, New Relic)
  • Log aggregation (ELK, Splunk)

3. Understand the Root Cause

Don’t just fix symptoms:

Root Cause Analysis

  • Ask “why” five times
  • Draw out system interactions
  • Review related code and changes
  • Check assumptions
  • Consider second-order effects

Common Root Causes

  • Incorrect assumptions
  • Edge cases not handled
  • Resource exhaustion
  • Race conditions
  • External dependency failures

4. Implement the Fix

Fix it right, not just fast:

Fix Quality

  • Address root cause, not symptoms
  • Add tests to prevent regression
  • Consider side effects
  • Review with team
  • Document the fix

Testing

  • Unit tests for the specific fix
  • Integration tests for interactions
  • Regression tests for related areas
  • Performance tests if relevant
  • Manual testing in realistic scenarios

5. Prevent Recurrence

Learn from every bug:

Prevention Strategies

  • Add automated tests
  • Improve error handling
  • Add monitoring and alerting
  • Update documentation
  • Share learnings with team

Systematic Improvements

  • Identify patterns in bugs
  • Address systemic issues
  • Improve development processes
  • Enhance tooling
  • Update coding standards

Performance Optimization Process

1. Measure Current Performance

Establish a baseline:

Key Metrics

  • Response times (p50, p95, p99)
  • Throughput (requests/second)
  • Error rates
  • Resource utilization (CPU, memory, I/O)
  • User experience metrics (LCP, FID, CLS)

Tools

  • Application Performance Monitoring (APM)
  • Real User Monitoring (RUM)
  • Synthetic monitoring
  • Profiling tools
  • Database query analyzers

2. Identify Bottlenecks

Find the 20% causing 80% of problems:

Profiling

  • CPU profiling to find hot spots
  • Memory profiling to find leaks
  • Database query profiling
  • Network request analysis
  • Render performance analysis

Analysis

  • Flame graphs for CPU usage
  • Heap dumps for memory
  • Slow query logs
  • Network waterfalls
  • User journey analysis

3. Optimize High-Impact Areas

Focus where it matters most:

Prioritization

  • Rank by performance impact
  • Consider implementation effort
  • Evaluate risk of changes
  • Quick wins first
  • Compound improvements

Common High-Impact Optimizations

  • Database query optimization
  • Caching implementation
  • Code-level algorithmic improvements
  • Asset optimization
  • Infrastructure scaling

4. Measure Improvements

Verify your optimizations worked:

Before/After Comparison

  • Same metrics as baseline
  • Statistical significance
  • Real-world user impact
  • Resource cost changes
  • Monitor for regressions

Continuous Monitoring

  • Set up performance budgets
  • Alert on degradation
  • Track trends over time
  • Regular performance reviews
  • Automated performance testing

Tools & Technologies

Debugging Tools

Backend

  • pdb/ipdb: Python debugging
  • Chrome DevTools: Node.js debugging
  • IEx: Elixir debugging
  • Delve: Go debugging
  • GDB: System-level debugging

Frontend

  • Chrome DevTools: Browser debugging
  • React DevTools: React inspection
  • Vue DevTools: Vue inspection
  • Redux DevTools: State debugging
  • Performance tab: Runtime performance

Profiling Tools

Application Profiling

  • py-spy: Python profiling
  • clinic: Node.js profiling
  • pprof: Go profiling
  • perf: Linux system profiling
  • Instruments: macOS profiling

Database Profiling

  • EXPLAIN/EXPLAIN ANALYZE: Query plans
  • pg_stat_statements: PostgreSQL stats
  • MySQL slow query log: Slow queries
  • MongoDB profiler: MongoDB analysis
  • Database-specific tools

Monitoring & APM

Application Monitoring

  • DataDog: Comprehensive APM
  • New Relic: Application performance
  • Dynatrace: Full-stack monitoring
  • AppDynamics: Enterprise APM
  • Sentry: Error tracking

Infrastructure Monitoring

  • Prometheus: Metrics collection
  • Grafana: Visualization
  • CloudWatch: AWS monitoring
  • Google Cloud Monitoring: GCP
  • Azure Monitor: Azure

Performance Testing

Load Testing

  • k6: Modern load testing
  • JMeter: Comprehensive testing
  • Locust: Python-based testing
  • Artillery: Node.js load testing
  • Gatling: High-performance testing

Browser Performance

  • Lighthouse: Web performance audits
  • WebPageTest: Detailed analysis
  • Chrome DevTools: Performance recording
  • SpeedCurve: Performance monitoring

Real-World Success Stories

E-Commerce Performance Rescue

Challenge: Checkout process taking 15+ seconds, 40% cart abandonment rate, losing $50K/day

Investigation

  • Profiled the entire checkout flow
  • Found N+1 database query problem
  • Discovered missing indexes
  • Identified inefficient API calls

Solution

  • Optimized database queries (added indexes, fixed N+1)
  • Implemented Redis caching layer
  • Refactored API to batch requests
  • Added database connection pooling
  • Implemented CDN for static assets

Results

  • Checkout time reduced to 2 seconds (87% improvement)
  • Cart abandonment dropped to 12%
  • Converted improvement to $800K additional annual revenue
  • Server costs reduced 30%
  • Customer satisfaction scores increased 45%

SaaS Memory Leak Fix

Challenge: Application crashing every 2-3 days, requiring restarts, customer complaints increasing

Investigation

  • Monitored memory usage patterns
  • Created heap dumps at regular intervals
  • Profiled long-running processes
  • Identified memory leak in event listeners

Solution

  • Fixed event listener cleanup
  • Implemented proper resource disposal
  • Added memory monitoring and alerts
  • Created automated leak detection tests
  • Refactored problematic code sections

Results

  • Zero crashes for 6+ months
  • Memory usage stable and predictable
  • Eliminated restart downtime
  • Improved application responsiveness
  • Saved engineering time from firefighting

API Response Time Optimization

Challenge: API response times degrading over time, p95 reaching 5+ seconds, users complaining

Investigation

  • Profiled all API endpoints
  • Analyzed database query performance
  • Reviewed caching strategy
  • Examined application architecture

Solution

  • Optimized 15 critical SQL queries
  • Implemented Redis caching for frequent reads
  • Added database read replicas
  • Implemented API response compression
  • Optimized JSON serialization

Results

  • p95 response time reduced to 200ms (96% improvement)
  • p50 response time down to 50ms
  • Database load reduced 60%
  • User satisfaction scores doubled
  • Supported 5x more concurrent users

Common Issues We Fix

Performance Issues

Slow Queries

  • Missing indexes
  • Inefficient query structure
  • N+1 query problems
  • Full table scans
  • Suboptimal join strategies

Memory Issues

  • Memory leaks
  • Excessive memory allocation
  • Inefficient data structures
  • Large object graphs
  • Caching gone wrong

Slow Response Times

  • Network latency
  • Inefficient algorithms
  • Blocking operations
  • Lack of caching
  • Over-fetching data

Functional Bugs

Logic Errors

  • Incorrect calculations
  • Edge cases not handled
  • Off-by-one errors
  • State management issues
  • Business logic mistakes

Integration Issues

  • API incompatibilities
  • Data format mismatches
  • Authentication/authorization bugs
  • Third-party service failures
  • Message queue problems

Concurrency Bugs

  • Race conditions
  • Deadlocks
  • Data corruption
  • Inconsistent state
  • Thread safety issues

Infrastructure Issues

Scaling Problems

  • Resource exhaustion
  • Connection pool limits
  • Database connection issues
  • File descriptor limits
  • Network bandwidth constraints

Configuration Issues

  • Incorrect settings
  • Environment-specific bugs
  • Missing environment variables
  • Certificate problems
  • Firewall/security issues

Getting Started

Emergency Support

Critical Issue Process

  1. Contact us with issue description
  2. Emergency team assembled (< 1 hour)
  3. Initial assessment and stabilization
  4. Root cause investigation
  5. Permanent fix implementation

Availability: 24/7 for critical production issues

Performance Assessment

Week 1: Discovery

  • Review architecture and codebase
  • Analyze current performance metrics
  • Profile application and database
  • Identify bottlenecks and issues
  • Create prioritized optimization plan

Week 2+: Implementation

  • Implement high-priority optimizations
  • Measure improvements
  • Iterate on additional optimizations
  • Document findings and recommendations
  • Train team on best practices

Retainer Support

Ongoing Bug Fixing & Optimization

  • Dedicated hours per month
  • Priority support
  • Continuous performance monitoring
  • Regular optimization reviews
  • Proactive issue identification

Typical Packages

  • Startup: 20 hours/month
  • Growth: 40 hours/month
  • Enterprise: 80+ hours/month

Investment & ROI

Typical Costs

One-Time Projects

  • Emergency bug fix: $2K - $10K
  • Performance optimization: $10K - $50K
  • Comprehensive system optimization: $50K - $150K

Retainer Support

  • Part-time: $5K - $10K/month
  • Full-time: $15K - $25K/month

Expected Returns

Direct Benefits

  • Reduced server costs (often 20-50%)
  • Increased conversion rates (1-5% typical)
  • Eliminated downtime costs
  • Reduced support tickets
  • Faster feature development

ROI Examples

  • E-commerce: 2-second load time improvement = 3% conversion increase
  • SaaS: Eliminating crashes = retained customers worth $100K+ annually
  • API service: 80% performance improvement = support 5x more users on same infrastructure

Most optimization projects pay for themselves within 3-6 months.

Why Choose Async Squad Labs?

Deep Technical Expertise

We’ve debugged it all:

  • Complex distributed systems
  • High-concurrency applications
  • Legacy codebases
  • Performance-critical systems
  • Multi-language stacks

Systematic Approach

We don’t guess, we investigate:

  • Scientific methodology
  • Data-driven decisions
  • Root cause analysis
  • Comprehensive testing
  • Documentation and knowledge transfer

Technology Agnostic

We work with your stack:

  • Python, JavaScript, Elixir, Go, Ruby, and more
  • All major frameworks and databases
  • Cloud platforms (AWS, GCP, Azure)
  • Containerized and serverless
  • Legacy and modern systems

Fast and Reliable

When you have a critical issue:

  • Rapid response times
  • Available 24/7 for emergencies
  • Experienced team ready to help
  • Clear communication throughout
  • Proven track record

Ready to Fix Your Issues?

Don’t let bugs and performance problems hold your business back. Whether you’re facing a critical production issue or want to proactively optimize your system, we’re here to help.

Get started today:

  • Emergency support: Contact us immediately for critical issues
  • Performance assessment: Schedule a free consultation
  • Retainer support: Discuss ongoing optimization needs

Contact us to eliminate the bugs and performance issues slowing you down.


Explore our other services: Software Development, Testing & QA, and Fast Feature Delivery.

Async Squad Labs Team

Async Squad Labs Team

Software Engineering Experts

Our team of experienced software engineers specializes in building scalable applications with Elixir, Python, Go, and modern AI technologies. We help companies ship better software faster.