If your business will develop games, software and application which you sell to your customers and they use it themselves or within their organization, you are looking at Activity 5.7.2 Enterprise software and/or digital content. This category gives you 5 year corporate income tax exemption, without a cap. That means any amount of profits from the promoted business will not be subject to income tax for 5 years. The income must be from the fee you charge to develop the software or subscription fees. This category has the condition that you need to spend Baht 1.5 M in IT personnel salaries each year.
If the software you will develop is a platform where there are at least 3 parties involved; for example, you as the job finding platform owner, companies who are seeking employees and job seekers, this is a software platform. You can get promoted by Thailand BOI in category 5.9, which gives you 5 year corporate tax exemption with the cap at the amount of your investment into this business. Suppose you buy computers, pay for office renovation, buy office furniture and other fixed assets totaling Baht 1 M (which is the minimum investment required for this category), then the amount of tax that you can save for the whole 5 years is Baht 1 M. This investment does not include cost of land or working capital. The only income you can earn in this category is for the use of your platform, not commission based.
If you want to develop a platform and will charge commission based on the transaction value, then you are looking at the BOI promotion in category 5.8 E-commerce. This one does not give any tax benefits but at least you can have many work permits for your foreign employees and you can own the business 100% (which also apply to category 5.7.2 and 5.9 mentioned above.
See more details in this list of BOI eligible activities here: https://thailawyers.com/wp-content/uploads/2017/10/section-5.pdf
Contact Thai Lawyers to help you register a Thai BOI company now.