The First 90 Days - Turning Software Modernisation into a Force Multiplier

When a newly appointed CTO or Engineering Leader asks “What should I focus on in my first 90 days?” The answer is clear. Build trust, diagnose before acting, and use data-driven insights to identify how your software platforms can act as a catalyst for growth.

What This Article Explores:

• How new CTOs and Engineering Leaders can build trust quickly.
• Why diagnosis before action prevents misalignment and poor decisions.
• How to balance early wins with long-term modernisation goals.
• The importance of data-driven insights in building credibility.
• How leadership behaviours influence culture, delivery performance, and alignment.
• Why the first 90 days are so critical to modernisation success.
• Insights from Codurance’s modernisation work and the UK IT Leaders Conference.

These themes took centre stage at this year’s UK IT Leaders Conference, where Codurance, a global software modernisation consultancy trusted by PE-backed and enterprise technology leaders, hosted a keynote session titled “The First 90 Days: Leading Legacy Modernisation That Pushes the Boundaries.” The discussion hosted by myself, Simon Shaw (Regional Director, Codurance), and, featuring Ian Kershaw (CTO, Artlogic), Rachel Hopkins (CIO, Arrow XL), and Steve Lydford (UK Managing Director, Codurance), explored how purposeful leadership during those crucial early months can turn software legacy modernisation into a strategic advantage, driving alignment, accelerating delivery, and inspiring confidence across teams.

What Should CTOs Prioritise in Their First 90 Days?

The first quarter sets the course for success. It is the time to align expectations, earn credibility, and show early momentum. Rather than focusing on sweeping change, start by learning the landscape. Understand who your stakeholders are, what success looks like for them, and how technology can best serve the business.

As highlighted by Harvard Business School, the first 90 days of leadership define long-term effectiveness, a principle that applies strongly to modernisation leaders today.

Quick wins matter but not at the expense of long-term strategy. Demonstrate early value while laying the foundation for sustainable improvement. This is your opportunity to show progress, build confidence, and establish your rhythm as a leader.

How Can Technology Leaders Build Trust Quickly?

Your first 90 days are an extension of the recruitment process, and you’re still being evaluated. Building trust quickly is vital. Start with empathy and open communication. If your first 90 days are in a new company, focus on understanding the culture and establishing credibility early. If it’s within a new role or project, take time to learn how success is defined and how your leadership can add value. In any scenario, create a psychological contract with your team that says, “I’ve got your back, and we’ll learn together.”

Show vulnerability, be visible, and listen more than you talk. When people see you take an interest in their challenges, they are more likely to support your vision. Recognise achievements early, highlight hidden successes, and make sure your team feels valued for the work they do.

Why Is Diagnosis Before Action Critical for Modernisation?

It is easy to form opinions early, but assumptions can lead to poor decisions. Instead, diagnose before acting. Use data-driven assessments to understand performance and identify the root causes of technical challenges.

Benchmark against industry standards to remove bias and ensure recommendations are evidence-based. Tools such as Codurance’s Software Quality Assessment (SQA) help you evaluate systems and processes objectively, providing a foundation for meaningful conversations with senior stakeholders.

This data also helps you secure executive buy-in and investment by demonstrating tangible risks and opportunities.

For additional information, McKinsey & Company notes that transformations are hard, and digital ones are harder, but having the right leadership tools in place is crucial to success.

How Can Leaders Balance Quick Wins with Long-Term Tech Strategy?

In the early months, it is about balance. Achieving visible quick wins while developing a sustainable roadmap is key. Some initiatives may appear low-effort but carry hidden complexity. Take time to understand each team’s skill level, context, and constraints before committing to major change.

Look for opportunities to introduce proven engineering practices that deliver immediate impact such as automation, CI/CD pipelines, and incident-management processes. Communicate progress transparently, share updates regularly, and avoid disappearing into a “black hole” of delivery.

For deeper insight, explore Codurance’s new Elite Performance - Achieving Speed & Stability with CI/CD & DevSecOps eBook which shows how modern delivery pipelines can become a competitive advantage.

When Should Leaders Reset Their 90-Day Plan?

The first 90 days should not be viewed as a one-off phase but as a repeatable framework. Major business events such as mergers, acquisitions, or organisational change often demand a renewed 90-day plan.

Use these inflection points to re-evaluate priorities, refocus efforts, and communicate a refreshed vision.

If something does not go as planned, take ownership early. Leadership strength often lies in how you respond to setbacks. Demonstrating accountability and courage restores confidence and rebuilds momentum across teams.

For further reading, Gartner’s leadership research explores how adaptive leaders thrive through change.

How Can Software Modernisation Drive Business Performance?

Software modernisation is one of the most complex challenges a technology leader can face. It demands technical vision, cultural awareness, and clear communication. When handled effectively, it becomes a force multiplier that improves speed, resilience, and alignment across the business.

The accelerating pace of cyber security, data, and AI adoption has made legacy modernisation even more urgent. But success depends less on tools and more on trust, transparency, and leadership.

Your first 90 days are the perfect window to align teams, secure investment, and create a culture where modernisation becomes a shared mission, not a top-down directive.

For a real-world example, explore our Artlogic case study where we helped address scalability, performance, and global coordination challenges to support impressive growth.

Conclusion - Leading with Confidence in the First 90 Days

The first 90 days are about more than settling in. They are a test of leadership, strategy, and self-awareness. By listening before acting, building trust, diagnosing with data, and balancing short-term progress with long-term vision, new technology leaders can turn their first 90 days into a platform for sustained success.

How Codurance Can Help

If you are embarking on your own leadership journey or facing a legacy modernisation challenge, Codurance can help. From global healthcare providers to market leading retailers, we work with the world’s most innovative businesses to enable their next stage of growth.

Our range of assessments including the Software Quality Assessment (SQA) and Data & AI Readiness Assessment (DARA) provide the data and insight you need to make confident decisions and secure stakeholder buy-in from day one.

Get in touch with us to speak to one of our specialists.

Frequently Asked Questions

1. What should a CTO focus on in their first 90 days? They should prioritise understanding the business context, earning trust, and creating a data-informed roadmap for modernisation.

2. How can software modernisation become a competitive advantage? By aligning teams around shared goals, improving speed and reliability, and using automation and CI/CD to accelerate delivery.

3. What tools can help assess legacy systems? Codurance’s Software Quality Assessment (SQA) provides objective analysis and actionable insights to guide transformation.

About the Author 

Simon Shaw is the Regional Director for UK North at Codurance. He helps organisation's accelerate modernisation, enhance delivery performance and build high-performing engineering culture 

Citations

1. Rebecca Carnahan, Harvard Business School (2023). Tackle the First 90 Days of Your Next Role: A 5 Step Process for Success on the Job - Alumni - Harvard Business School
2. McKinsey & Company (2018). Unlocking success in digital transformations 
3. Gartner Insights (2023). Essentials for Executives Taking a New Role