About Me
A certified professional DBA with over twenty five years experience working with database and internet technologies and infrastructure. Vast experience developing, tuning and troubleshooting both databases and applications running on Oracle, Microsoft SQL Server, MySQL and others.
Worked on numerous high profile client facing projects for PeopleSoft (now Oracle) including production and development roles, and has also implemented and supported many projects for Higher Education Universities and Further Education Colleges across the UK. Recent projects include full cycle IT Support and PL/SQL interface development, as well as managing and supporting the database and internet architecture and end user systems at Adecco on the rollout of PeopleSoft’s Financials package.
Contact
- Email: jonathancellis@outlook.com
- Phone: (44) 07968 730942
- LinkedIn: /in/jonathanellis
Core Skills
Education
BSc Computer Science
Open University | 1999 – 2005
Oracle Certified Professional
Oracle | 2001 – 2002
Experience
Technical Product Manager
Paul Mason Consulting Ltd
Jan 2013 – July 2025 | Abingdon, UK
- Led the Technical Product Specialists and DBA Services teams at PMC.
- Responsible for maintaining and developing the managed services tool set including a bespoke retail focussed UEM solution. Technical consultancy to the retail sector.
- Oracle & SQL Server DBA activities and consultancy.
Owner/Consultant
eTune Consulting Ltd
May 2006 – Jan 2013 | UK & Europe
- Consultant Peoplesoft/Oracle DBA and developer for clients such as Rabobank, Rotterdam College of Further Education, Adecco and Credit Suisse.
- Technical Architect for merger of Ajilon Recruitment and Adecco UK - interface design and development from legacy systems into PeopleSoft utilising Oracle PL/SQL. Installation of PeopleSoft UK environments across Borehamwood and London.
- Lead developer for bespoke data bus to extract, transform and load data into the new PeopleSoft HR & Financials systems.
Peoplesoft Technology Consultant
Peoplesoft UK
May 1999 – Jan 2004 | Reading, UK
- DBA/PeopleSoft administrator on various project teams for many blue chip clients including Bupa, Sainsbury, Carrefour France, Nationwide Building Society.
- Lead consultant for PeopleSoft's Global Payroll rollout in the UK facilitating the UAT and technical testing program.
Key Projects
Rabobank Peoplesoft Financials
View Client →Full lifecycle project DBA including installation, configuration, performance tuning and backup strategies, through to go live. A full Peopleosft financials implementation with development of IBM databus and associated interfaces.
Adecco Peoplesoft HR Deployment
View Client →Full lifecycle project DBA through to go live. Lead developer, interfacing legacy systems into the Peoplesoft Oracle database using ETL and Oracle PL/SQL. Responsible for disaster recovery configuration and policies.
Detailed Skills
SQL & Procedural SQL
Deep understanding and experience of writing SQL statements in Oracle and Microsoft SQL Server. Expertise in PL/SQL (or equivalent procedural extensions like T-SQL), enabling the design and implementation of robust, scalable stored procedures, functions, triggers, and packages.
Database Administration
Database installation, configuration, and patching (including high-availability configurations like clustering and replication). Ensures optimal performance through advanced techniques such as query tuning, index optimisation, and memory/storage configuration (e.g., managing buffer pools and I/O settings).
Wordpress & Web Design
Deep proficiency in the WordPress ecosystem beyond simple theme customisation. This includes custom theme and plugin development using PHP, modern JavaScript (e.g., React/Vue), and advanced WordPress APIs to build bespoke functionality. Advanced HTML5, CSS3/Sass, and modern responsive frameworks (like Tailwind or Bootstrap) to ensure pixel-perfect, cross-browser compatibility.
Personal Projects & Hobbies
Revival Records
Go To Website →Revival Records since 1996, primarily to digitise and restore old vinyl to digital music for customers when the demand was high. Nowadays we have a slowly growing online shop, post and blog about music, review vinyl and other physical media, restore and sell vintage hifi equipment, and buy up unwanted records to rehouse them.
Retro Computing
Go To Website →A retrocomputing blog. Adventures with a Commodore 64 in the 21st Century. Coding, projects, Advent of Code, 6502 Machine Language.